Risk of Hospitalization for Serious Adverse Gastrointestinal Events Associated With Sodium Polystyrene Sulfonate Use in Patients of Advanced Age.

Importance: Sodium polystyrene sulfonate is commonly prescribed for the treatment of hyperkalemia. Case reports of intestinal injury after administration of sodium polystyrene sulfonate with sorbitol resulted in a US Food and Drug Administration warning and discontinuation of combined 70% sorbitol-sodium polystyrene sulfonate formulations. There are ongoing concerns about the gastrointestinal (GI) safety of sodium polystyrene sulfonate use. Objective: To assess the risk of hospitalization for adverse GI events associated with sodium polystyrene sulfonate use in patients of advanced age. Design, Setting, and Participants: Population-based, retrospective matched cohort study of eligible adults of advanced age (≥66 years) dispensed sodium polystyrene sulfonate from April 1, 2003, to September 30, 2015, in Ontario, Canada, with maximum follow-up to March 31, 2016. Initial data analysis was conducted from August 1, 2018, to October 3, 2018; revision analysis was conducted from February 25, 2019, to April 2, 2019. Cox proportional hazards regression models were used to examine the association of sodium polystyrene sulfonate use with a composite of GI adverse events compared with nonuse that was matched via a high-dimensional propensity score. Additional analyses were limited to a subpopulation with baseline laboratory values of estimated glomerular filtration rate and serum potassium level. Exposure: Dispensed sodium polystyrene sulfonate in an outpatient setting. Main Outcomes and Measures: The primary outcome was a composite of adverse GI events (hospitalization or emergency department visit with intestinal ischemia/thrombosis, GI ulceration/perforation, or resection/ostomy) within 30 days of initial sodium polystyrene sulfonate prescription. Results: From a total of 1 853 866 eligible adults, 27 704 individuals were dispensed sodium polystyrene sulfonate (mean [SD] age, 78.5 [7.7] years; 54.7% male), and 20 020 sodium polystyrene sulfonate users were matched to 20 020 nonusers. Sodium polystyrene sulfonate use compared with nonuse was associated with a higher risk of an adverse GI event over the following 30 days (37 events [0.2%]; incidence rate, 22.97 per 1000 person-years vs 18 events [0.1%]; incidence rate, 11.01 per 1000 person-years) (hazard ratio, 1.94; 95% CI, 1.10-3.41). Results were consistent in additional analyses, including the subpopulation with baseline laboratory values (hazard ratio, 2.91; 95% CI, 1.38-6.12), and intestinal ischemia/thrombosis was the most common type of GI injury. Conclusions and Relevance: The use of sodium polystyrene sulfonate is associated with a higher risk of hospitalization for serious adverse GI events. These findings require confirmation and suggest caution with the ongoing use of sodium polystyrene sulfonate.

A novel hirudin derivative inhibiting thrombin without bleeding for subcutaneous injection.

Currently, anticoagulants would be used to prevent thrombosis. Thrombin is an effector enzyme for haemostasis and thrombosis. We designed a direct thrombin inhibitor peptide (DTIP) using molecular simulation and homology modelling and demonstrated that the C-terminus of DTIP interacts with exosite I, and N-terminus with the activity site of thrombin, respectively. DTIP interfered with thrombin-mediated coagulation in human, rat and mouse plasma (n=10 per group) and blocked clotting in human whole blood in vitro. When administered subcutaneously, DTIP showed potent and dose-dependent extension of aPTT, PT, TT and CT in rats (n=10 per group). The antithrombotic dose of DTIP induced significantly less bleeding than bivalirudin determined by transecting distal tail assay in rats. Furthermore, DTIP reached peak blood concentration in 0.5-1 hour and did not cause increased bleeding after five days of dosing compared to dabigatran etexilate. The antithrombotic effect of DTIP was evaluated in mice using lethal pulmonary thromboembolism model and FeCl3-induced mesenteric arteriole thrombus model. DTIP (1.0 mg/kg, sc) prevented deep venous thrombosis and increased the survival rate associated with pulmonary thromboembolism from 30 % to 80 %. Intravital microscopy showed that DTIP (1.0 mg/kg, sc) decelerated mesenteric arteriole thrombosis caused by FeCl3 injury. These data establish that DTIP is a novel antithrombotic agent that could be used to prevent thrombosis without conferring an increased bleeding risk.

A Case of Idiopathic Mesenteric Phlebosclerosis with Progressive Intestinal Necrosis.

The patient was a 39-year-old woman who was referred to our department from her previous doctor with a 2-day history of right abdominal pain. Abdominal computed tomography showed wall thickening associated with calcification in the ascending colon. Contrast enhancement in the same portion of the intestinal wall was rather poor. Fluid accumulation was also seen around the intestine, so emergency surgery was performed under a provisional diagnosis of intestinal necrosis. Intestinal necrosis due to idiopathic mesenteric phlebosclerosis was diagnosed from postoperative histopathological tests. Idiopathic mesenteric phlebosclerosis displays a chronic course and in most cases conservative treatment is indicated. Bowel obstruction is common among patients who require surgical treatment, but rare cases such as the present one are also seen in which intestinal necrosis occurs. In recent years, an association with herbal medicine has been indicated as one potential cause of this disease, and this entity should be kept in mind when patients with acute abdomen and a history of taking herbal medicines are encountered.

Defective thrombus formation in mice lacking endogenous factor VII activating protease (FSAP).

Factor VII (FVII) activating protease (FSAP) is a circulating protease with a putative function in blood coagulation and fibrinolysis. Genetic epidemiological studies have implied a role for FSAP in carotid stenosis, stroke and thrombosis. To date, no in vivo evidence is available to support these claims. We have, for the first time, used FSAP-/- mice to define its role in thrombosis and haemostasis in vivo and to characterise the molecular mechanisms involved. FeCl3-induced arterial thrombosis in carotid and mesenteric artery revealed that the occlusion time was significantly increased in FSAP-/- mice (p< 0.01) and that some FSAP-/- mice did not occlude at all. FSAP-/- mice were protected from lethal pulmonary thromboembolism induced by collagen/ epinephrine infusion (p< 0.01). Although no spontaneous bleeding was evident, in the tail bleeding assay a re-bleeding pattern was observed in FSAP-/- mice. To explain these observations at a mechanistic level we then determined how haemostasis factors and putative FSAP substrates were altered in FSAP-/- mice. Tissue factor pathway inhibitor (TFPI) levels were higher in FSAP-/- mice compared to WT mice whereas FVIIa levels were unchanged. Other coagulation factors as well as markers of platelet activation and function revealed no significant differences between WT and FSAP-/- mice. This phenotype of FSAP-/- mice could be reversed by application of exogenous FSAP. In conclusion, a lack of endogenous FSAP impaired the formation of stable, occlusive thrombi in mice. The underlying in vivo effect of FSAP is more likely to be related to the modulation of TFPI rather than FVIIa.

[Serious complications to a weight loss programme with HCG]. / Alvorlig komplikation i forbindelse med slankekur med humant choriongonadotropin.

A 28-year-old woman presented with abdominal pain. Prior to admission she had injected human chorionic gonadotropin (hCG) intramuscularly as part of a weight loss programme. A computed tomography detected a thrombosis of the superior mesenteric vein and with a gynaecologic scan she was found to be six weeks pregnant despite using oral contraception. Treatment with anticoagulant therapy was started, and a surgical abortion was performed. hCG bought illegal is used as a part of a weight loss program. Whether HCG injected in small amounts is a risk factor of venous thrombosis and whether it is able to reduce the effect of oral contraception is unknown.

Mesenteric phlebosclerosis associated with long-term oral intake of geniposide, an ingredient of herbal medicine.

BACKGROUND: Idiopathic mesenteric phlebosclerosis (IMP) is a rare disease, characterised by thickening of the wall of the right hemicolon with calcification of mesenteric veins. However, the aetiology remains unknown. AIM: To investigate the possible association of herbal medicines with IMP. METHOD: The clinical data of four of our own patients were collected. Furthermore, we searched for previous reports about similar patients with detailed descriptions of herbal prescriptions that they had taken. We compared herbal ingredients to identify the toxic agent as a possible aetiological factor. RESULTS: Clinical data on a total of 25 patients were summarised. Mean age was 61.8 years and there was female predominance (6 men and 19 women). The used Kampo prescription, the number of cases, and the mean duration of use were as follows: kamisyoyosan in 12 cases for 12.8 years, inshin-iseihaito in 5 cases for 13.4 years, orengedokuto in 4 cases for 14.3 years, inchinkoto in 1 case for 20 years, kamikihitou in 1 case for 19 years, seijobofuto in 1 case for 10 years and gorinsan in 1 case for an unknown duration. Only one ingredient, sansisi, was common to the herbal medicines of all 25 patients. This crude drug called geniposide in English is a major constituent of the Gardenia fruits. CONCLUSION: The long-term use of geniposide in herbal medicines appears to be associated with mesenteric phlebosclerosis.

Essential domains of a disintegrin and metalloprotease with thrombospondin type 1 repeats-13 metalloprotease required for modulation of arterial thrombosis.

OBJECTIVE: A disintegrin and metalloprotease with thrombospondin type 1 repeats-13 (ADAMTS13) inhibits platelet aggregation and arterial thrombosis by cleavage of von Willebrand factor. However, the structural components of ADAMTS13 required for inhibition of arterial thrombosis are not fully defined. METHODS AND RESULTS: Using recombinant proteins and a murine model, we demonstrated that an ADAMTS13 variant truncated after either the eighth thrombospondin type 1 repeat or the spacer domain inhibits ferric chloride-induced arterial thrombosis in ADAMTS13(-/-) mice with efficacy similar to that of full-length ADAMTS13. The results obtained from monitoring thrombus formation in carotid and mesenteric arteries were highly concordant. Further analyses by site-directed mutagenesis and human monoclonal antibody inhibition assay revealed that the Cys-rich and spacer domains of ADAMTS13, particularly the amino acid residues between Arg559 and Glu664 in the spacer domain, may be critical for modulation of arterial thrombosis in vivo. Finally, the thrombosis-modulating function of ADAMTS13 and variants/mutants was highly correlated with the von Willebrand factor-cleavage activity under fluid shear stress. CONCLUSIONS: Our results suggest that the amino terminus of ADAMTS13, specifically the variable region of the spacer domain, is crucial for modulation of arterial thromboses under (patho)physiological conditions. These findings shed more light on the structure-function relationship of ADAMTS13 in vivo and may be applicable for rational design of protein- or gene-based therapy of arterial thromboses.

A case of thrombosis of the superior mesenteric vein occurring in a young woman taking oral contraceptives: full and fast resolution with low molecular weight heparin.

Mesenteric venous thrombosis (MVT) is an unusual site of deep venous thrombosis. Little is known about risk factors of MVT, but available data seem to confirm a pathogenetic role of acquired thrombotic risk factors as well as inherited thrombotic risk factors. However, few cases on the association of MVT with oral contraceptive use have been described. We here report a case of MVT in a woman on oral contraception with fine and complete resolution after a fast diagnosis with abdominal ultrasound imaging and prompt therapy based on low molecular weight heparin.

[Influence of cardiac circulation and medication on the perfusion of the intestine]. / Einfluss der kardialen Zirkulation und einer herzwirksamen Medikation auf die Durchblutung der Bauchorgane.

Perfusion of the abdomen is determined by cardiac function and circulation. Intestinal ischemia can be caused by Non occlusive bowel ischemia (NOD) that is important in internal as well as surgical intensive care medicine. Cardiac medication can influence perfusion of the bowel: 1) digitalis increases muscular tonus and decreases perfusion regulation b) diuretics lead to hypovolemia, hypotonia and malperfusion, c) antihypertensive medication can cause intraoperative hypotension that demands catecholamines, d) catecholamines can reduce perfusion by pathologic vasoconstriction in the splanchnicus area. Preoperative medication should respect 1) preoperatively taken ACE-inhibitors should be given postoperatively, as they have protective influence on the microcirculation of the bowel, 2) beta-blockers stabilize the myogenic tonus of the abdominal vessels, reduce an overshot of the parasympatheticus and diminish the risk of neurogenic abdominal shock, 3) catecholamines should be used with respect to ischemia of the bowel. Therapy of NOD should be focused on the primary vascular and hemodynamic causes and also take care for bacterial translocation and consecutive sepsis.

Propranolol-exacerbated mesenteric ischemia in a patient with hyperthyroidism.

OBJECTIVE: To report a case of acute mesenteric ischemia associated with the use of oral propranolol. CASE SUMMARY: A 59-year-old white man was admitted to the hospital with chronic diarrhea and weight loss. The patient was diagnosed as having hyperthyroidism. Therapy with propylthiouracil 100 mg 3 times daily and propranolol 20 mg twice daily was initiated on an outpatient basis. The following day, the patient was readmitted to our hospital with increased abdominal pain and bloody diarrhea. Angiography revealed superior mesenteric artery occlusion. Antegrade aorta-mesenteric bypass surgery was performed for revascularization, and the patient was discharged 10 days after the surgery. The patient was well both clinically and endoscopically at a follow-up visit 8 months later. DISCUSSION: Although mesenteric ischemia is a devastating illness of varied causes, drug-associated mesenteric ischemia is rarely seen. By decreasing cardiac output and selective vasodilatory receptor inhibition in the splanchnic circulation, propranolol can cause a decline in splanchnic blood flow. An objective causality assessment indicated that propranolol was the possible cause of the arterial occlusion. CONCLUSIONS: Propranolol may rarely be associated with mesenteric ischemia. In cases of newly developed acute abdomen undergoing propranolol therapy, physicians should be aware of this rare and serious adverse reaction to this drug.

Coingestion of cyclooxygenase inhibitors can worsen severe paracetamol poisoning by middle-sized and small arteries vasoconstriction.

OBJECTIVE: We report fatal cases of multifocal ischemic injuries occurring in patients awaiting liver transplantation after severe concomitant paracetamol and cyclooygenase inhibitors self-poisoning. DESIGN AND SETTING: Case report in an intensive care unit. PATIENTS: In addition to signs of acute liver failure with a systemic inflammatory response syndrome, these three previously healthy young women demonstrated cutaneous vasoconstriction. One patient displayed a sudden ST-segment elevation with ventricular fibrillation. INTERVENTIONS: Angiography, plasma endothelin concentrations measurements, and autopsy. RESULTS: Radiography showed diffuse vasospasm on mesenteric and renal arteries, transiently reversed by vasodilators. We measured tenfold higher plasma endothelin concentrations than in healthy controls. Autopsy revealed no atherosis (including coronary arteries); organs showed multifocal ischemic injuries without thrombosis. CONCLUSIONS: Such injuries subsequent to dramatic vasoconstriction suggest that cyclooygenase inhibition has specific deleterious vascular side effects once systemic inflammatory response syndrome is in progress during paracetamol poisoning.

Acute abdomen during adjuvant chemotherapy: superior mesenteric artery thrombosis associated with CMF chemotherapy.

We report a case of superior mesenteric artery thrombosis in a 57-year-old woman undergoing chemotherapy for T1N1M0, breast cancer. Although cancer itself is associated with an increased risk of thrombotic events, treatment with chemotherapy and/or tamoxifen in breast cancer patients increases this risk. Most cases reported are of venous thromboembolism; arterial events are rare.

Mesenteric venous thrombosis attributed to docetaxel.

We present a case of a 57-year-old woman with metastatic breast cancer unresponsive to several chemotherapeutic and hormonal regimens. Because of progressive pulmonary metastases and a painful osteolytic metastasis in the sternum, treatment with docetaxel was initiated. She developed mesenteric venous thrombosis within 1 week after the first dose of docetaxel. Although docetaxel may be regarded as an important advancement in the chemotherapeutic treatment of several cancers, ongoing and future trials must assess its position in the standard chemotherapeutic treatment of cancer. Well-documented adverse reactions, either common or rare, may contribute to a balanced risk-benefit profile of docetaxel.